1. Field of the Invention
The invention relates generally to pulsatile flow systems, and more particularly, to s a pulsatile flow system that mimics the pumping of a human heart.
2. Description of Related Art
Systems that provide a pulsatile, or non-continuous, flow are used in a variety of applications. Such pulsatile flow systems are often employed for functional and reliability testing of medical devices designed to work in conjunction with a beating heart, for example, mechanical heart valves or implantable blood pumps.
Implantable blood pumps generally fall into two categories: total "artificial hearts," employed to completely replace a human heart which is not functioning properly; or "ventricle assist devices (VADs)," used to boost blood circulation in patients whose heart still functions but is not pumping blood at an adequate rate. Total artificial hearts completely replace a native heart. In contrast, VADs and mechanical valves designed to replace defective heart valves operate in conjunction with a native heart. Prior to implanting VADs or other mechanical devices in a patient to operate in conjunction with the patient's heart, it is desirable to insure that the devices operate properly and possess the required reliability characteristics. Such devices may be tested by operating them in a system that provides a pulsatile fluid flow therethrough, replicating the heart's pumping of blood.
The human heart beats more than 30 million times in a single year and pumps more than 4,300 gallons of blood a day. Thus, in an average lifetime of 70 years, the heart beats more than 2.5 billion times and pumps 1 million barrels of blood. Therefore, to obtain adequate reliability data on a VAD or other device that is to be operated with a beating heart, the device typically must be operated continuously for an extended time period.
Unfortunately, many existing pulsatile flow systems are not designed for such continuous, extended operation. Moreover, existing systems are often complicated and expensive. The estimated need for a long-term VAD is presently projected at between 50,000 and 100,000 patients per year in the United States alone. Thus, a need exists for a simple, yet reliable, pulsatile flow system for testing such devices.
The present invention addresses these, and other, shortcomings associated with the prior art.